Supercomputer set to revolutionise weather forecasting

Data from the world's biggest computer could soon bring about a major change in forecasting the world's weather.

Researchers expect the giant Earth Simulator supercomputer to provide the first reliable long term predictions of major storms, heatwaves and coldsnaps.

As a result countries will be better prepared for the extreme effects of global warming.

For Britain, it could mean weather such as this summer's heatwave, or the heavy rains of 2000, is less likely to take the country by surprise.

Early results from the new mammoth computer, based in Japan, were presented recently to scientists at a Cambridge University meeting.

Opened in March 2002, the Earth Simulator is dedicated to tracking climate and weather.

It takes up as much space as four tennis courts and consists of 640 "nodes", each one equivalent to an individual computer, linked together by 83,000 high speed cables.

The computer is 40 times faster than any other machine in operation in the world.

It will enable scientists to tell years in advance whether storms or droughts can be expected in specific regions of the Earth.

Professor Julia Slingo, director of the Natural Environment Research Council's NCAS Centre for Global Atmospheric Modelling, said: "These results are very exciting. They show that, for the first time, our climate models can be run at resolutions capable of capturing severe weather events such as intense depressions, hurricanes and major rainstorms.

"This means that we potentially have the capability to predict whether storms, like Hurricane Isabel, will be on the increase in future.

"Importantly for the UK, we will be able to predict with more confidence increases in damaging storms and extremes in temperature, and what their regional impacts will be.

"They will help us to prioritise our investment in devising strategies to adapt to climate change, for example the specification of railway lines to deal with the extreme heat experienced this summer, or storm drains to cope with extreme rainfall, such as we experienced in the autumn of 2000."

Huge amounts of computing power are needed to estimate the likely long term impacts of climate change.

A single program might be written by hundreds of specialist experts and run for months.

Even so, the best supercomputers to date have only been able to predict far off weather trends in regions no smaller than 250 square kilometres.

The Earth Simulator takes this resolution down to 10 square kilometres - small enough to encompass individual storm systems.

Dr Dave Griggs, director of the Hadley Centre for Climate Prediction and Research in Bracknell, Berkshire, said: "For ordinary weather forecasts you only have to run the model for a couple of days, so the resolution is much higher. But for climate prediction you have to run it for 100 years.

"The Earth Simulator won't be able to say that on September 17, 2017 you will get a tornado. But it will be able to say that by the 2080s there will be hurricanes up to 20 per cent more intense than they are today and twice as frequent.

"Because of the high resolution the predictions will be more local. For instance, you will be able to forecast more flooding in northern Europe and more droughts in southern Europe."

He said Britain, which has some of the leading climate scientists in the world, had been granted access to the computer as part of a joint project between the two countries.

But because even with the Earth Simulator it took so long to run climate models, the practical benefits may not be seen for another year.